/Engine/Source/Runtime/GeometryCore/Public/DynamicMesh/DynamicPointSet3.h
Insert vertex at given index, assuming it is unused. If bUnsafe, we use fast id allocation that does not update free list. You should only be using this betweenBeginUnsafeVerticesInsert()/EndUnsafeVerticesInsert()calls
[EMeshResult](API\Runtime\GeometryCore\UE__Geometry__EMeshResult) InsertVertex ( int VertexID, const [TVector](API\Runtime\Core\Math\TVector)< RealType > & Position, bool bUnsafe )